Збірники наукових праць ЦНТУ
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Item Травмування зерна пшениці зерноочисною машиною ОВУ–25 та шляхи його зниження(ЦНТУ, 2019) Писарькова, І. О.; Писарькова, И. О.; Pisarkova, I.Проведені дослідження з визначення рівня механічного травмування зерна при первинному очищенні машиною ОВУ–25. Отримана залежність коефіцієнта пошкодження (Kп, %) зерна від вологості (W, %) в різних зонах машини. Данні служать для вибору геометрії поверхонь робочих органів очисника вороху з метою зниження травмування зерна. Проведены исследования для определения уровня механического травмирования зерна при первичной очистке на машине ОВУ–25. Полученны зависимости коэффициента повреждения (Kп,%) зерна от влажности (W,%) в разных зонах машины. Данные служат для выбора геометрии поверхностей рабочих органов очистителя вороха с целью снижения травмирования зерна. nvestigation of the influence of the operating and transporting parts of the universal heap cleaner OVU-25 on damage and seed quality in order to ensure minimal influence of the operating parts of technical means on grain material in preparation for long-term storage due to repeated processing on technological equipment. The zones of greatest influence of the operating parts of grain cleaning machine OVU-25 in contact with the particles of the processed material are determined. Experimental studies were conducted to identify the level of mechanical damage of the grain during the initial cleaning by this machine. The quantitative composition of the operating parts and their technological characteristics were determined. The experimental data of the damage factor (Kp,%) of grain from humidity (W,%) in different operating zones of the machine on the basis of which graphical dependences were obtained. The influence of technological parameters of the operating parts on damage of grains was also identified. It has been established that the maximum damage of grain occurs in contact with the scrapers of conveyors, and the least damage occurs in the aspiration channels of the air purification system. Factors affecting the damage to the particles of the treated material were also investigated and identified. It is established that the damage of grains is influenced by the conditions of their contact with the surfaces, the characteristics of the contact surfaces, the length of the path of movement of the material, the speed of its movement and strokes during the cleaning process. All these observations make it possible to identify the drawbacks of the technological schemes of similar grain-cleaning machines and to substantiate proposals for changes in the structures of operating and transporting parts, materials and geometry of contact surfaces. The data are used to select the geometry of the surfaces of the operating parts of the heap cleaner in order to reduce grain damage.Item Механічне травмування насіння(ЦНТУ, 2018) Скринник, І. О.; Пісарькова, І. О.; Петренко, М. М.; Скринник, И. А.; Писарькова, И. А.; Петренко, Н. Н.; Skrynnik, I.; Pisarkova, I.; Petrenko, M.Отримані залежності відношення нормальної до поверхні складової швидкості зернівки пшениці після удару по поверхні до швидкості удару (аналог коефіцієнта миттєвого тертя, від якого залежить травмування зерна) і коефіцієнта травмування насіння від швидкості удару поповерхні, кута її нахилу, матеріалу, геометрії, вологості зерна. Ці дані служать для вибору режимів роботи машин для післязбиральної обробки зерна і геометріїповерхонь їх робочих органів. Получены зависимости отношения нормальной к поверхности составляющей скорости зерновки пшеницы после удара по поверхности к скорости удара (аналог коэффициента мгновенного трения, от которого зависит травмирование зерна) и коэффициента травмирования семян от скорости удара по поверхности, угла ее наклона, материала, геометрии, влажности зерна. Эти данные служат для выбора режимов работы машин для послеуборочной обработки зерна и геометрии поверхностей их рабочих органов. The objective of the article is to establish the influence of various factors on the ratio of the normal to the surface of the wheat grain velocity component after impact on the impact velocity (the analogue of the coefficient of instant friction which influences grain damage). Another objective is the study of the dependence of damage in the process of its interaction with the surfaces of working elements of machines on speed impact with the surface, its tilt angle, material, geometry and grain humidity. It has been established that when the angle of impact of grain with the surface increases, then the normal component of velocity after impact is reduced. It determines the rate of the dynamic load on the grain. Therefore, with the increaseof the angle of impact, the proportion of damaged grains decreases. Under impact loads, the destruction (damage) of grains takes place due to stresses (tension) that occur in the place contact of grains and the surface. The tension is directly proportional to the impact force and inversely proportional to the contact area.The contact area depends on the rate of the elastic deformation of the bodies: grain – surface, which increases with the decrease of the elastic modulus of the surface materials and grains. With the increase in the velocity of impact, the restitution factor decreases because part of the energy of grain deformation goes to its local destruction. At the same time, the values of the coefficients of grain damage increase accordingly with increasing velocity (from 1 m/s to 11 m/s). When impacting with the outside surface of the cylinder, the damagecoefficient of the grain decreases with the increase in the angle of impact and the decrease in cylinder diameter. It mainly happens due to reducing the damage of the shell, as this reduces the time of contact of the grain with a convex curvilinear surface after impact. When the grain impactswith the inner cylindrical surface, the degree of grain damage increases due to the increase in the time of the slip of the grain on the surface. It was established that the percentage of grain damage is the smallest in the range of moisture of the grainsat W = 12.7-15.3%, which can be rational in the case of clearing wheat grains by machines. Reducing or increasing this rate leads to the increase in the percentage of grain damage. Therefore, grain damage during the impact can be reduced by choosing rational technological modes of operation, the geometry of surfaces of working elements of grain cleaning machines and their coatings.